Art of manufacturing pipe and tubing



Aug. 26, 1941. J. a SHOOK ART OF MANUFACTURING PIPE AND TUBING 2 Sheets-Sheet 1 Filed Feb. 13, 1940 INVENTOR.

A TTO RNEYS ii wm .2: immmmrmmmmmmmmv Patented Aug. 26, 1941 ART OF MANUgAC TUBING PIPE AND UBING John E. Shook, Sharon, Pa., assignor to Mercer Tube and Manufacturing Company, Sharon, Pa., a corporation of Delaware Application February 1 3, 1940, Serial No. 318,731

9 Claims.

This invention relates to the art of manufacturing pip and tubing and more particularly to the manufacture ofbutt and lap-weld pipe or tubing from heated skelp and embodying the well known draw bench bell-weld method.

As heretofore practiced the apparatus employed and the methods followed contemplate a furnace having a heating chamber into which the skelp is introduced onto the hearth of the furnace through a large opening at the rear of the furnace; such an opening being for example ten feet wide by an average of seven inches high. The skelp is charged into the furnace through the said opening, one piece at a time and is laid side by side across the full width of th hearth by the employment of magnetic or other charging machines. Such machine, in order to accomplish the charging properly, is caused to travel throughout the width of the said opening.

The front part of the furnace, is provided with a similar large opening for the withdrawal of the v skelp. The skelps are withdrawn one at a time by means of a traveling draw-bench arranged adjacent the opening in the front wall of the furnace.

It is evident that a furnace constructed as above described, having the large openings formed in the rear and front walls of the furnace, creates cold zones at each end of the furnace making it impossible to uniformly and completely heat the skelp throughout its length, thus causing considerable waste, as the ends of the skelp do not have the proper uniform temperature for welding treatment along the drawbench and through the usual bell.

Such uneven heating, makes it necessary to cut oil? a considerable amount of each piece of pipe at each end thereof, after it is formed on the draw-bench. This results in a loss of pipe, which, no matter how closely controlled, will average from five percent to six and one-half percent of the total amount of steel, skelp etc. charged into the furnace. The large openings above described admit great quantities of cold air and the effective heat of the furnace is greatly reduced.

The large opening at the front of the furnace, permitting as it does the passage of intense heat from the interior of the furnace, greatly interferes with the welder or operator in manipulating the tongs and other devices employed for withdrawing the skelp from the furnace.

Under methods as heretofore followed the time of withdrawal of the skelp depends entirely upon the skill of the welder, and it frequently happens that it is drawn too soon or too late to produce good results in the formation and'welding of the Pine.

Among the objects of the present invention are: to eliminate the large openings at the rear and the front of the furnace; to do away with the expensive and cumbersome traveling charging apparatus; to eliminate the traveling drawbench at the front of the furnace; and to provide automatically operable means for conveying the skelp at predetermined speeds through the furnace from one side thereof to an opposite side to effect the desired heat temperatures.

My invention contemplates, in lieu of the large charging and withdrawing openings, relatively small openings, for example, openings not in excess of ten inches by fifteen inches. Said openings are arranged out of alinement one with the other, thus preventing an excessive draft through the heating chamber; and the employment of fixedly positioned charging and withdrawing devices in place of the traveling charging device and the traveling draw-bench heretofore employed.

A further important and characteristic feature of the present invention resides in an automatically operable conveyor for the skelp extending from the small charging opening in the rear wall to the exit or withdrawal opening located in the front wall at a diagonally opposite end of the furnace whereby to produce in cooperation with the charging and draw-bench apparatus means for a continuous practically closed heating chamber of the furnace for effective pipe and tube-forming operations.

It will thus be seen that heat conservation will be maintained throughout the furnace interior between th charging and discharging openings.

It will be understood that the conveyor may be operated at predetermined and variable speeds depending for instance on the different widths and gauges of skelp being heated, and that by means of the automatically operable conveyor the assurance is had that each piece or skelp during its travel from the inletto the outlet opening will gradually attain the desired temperature, with uniformity throughout the full length of the skelp.

In the accompanyingdrawings which illustrate an application of my invention:

Fig. 1 is a diagrammatic plan view of apparatus embodying my invention;

Fig. 2, a detail cross sectional view on the line 1I--II of Fig. 1 showing means for conveying skelp to the charging machine for the furnace;

Fig. 3, an enlarged section of the furnace and the skelp conveyor operable therein, the section being taken on line III-III of Fig. 1; and

Fig. 4, a detail sectional view on the line IV-IV of Fig. 3, particularly showing the water cooled conveyor rail or track and the conveyor thereon.

Referring to the drawings 5 designates a furnace of the regenerative type, although some other type of furnace may be employed. As 11- lustrated 6 designates a rear wall of the furnace and I a front wall. The rear wall is formed with a relatively small material charging opening 8, and the front wall with a similar opening 9, through which latter opening the skelp is withdrawn after its passage through the heating chamber of the furnace. With the exception of the said openings the rear and front walls preferably constitute a solid construction.

The term skelp" is used herein to cover any product from which pipe or tubing are made, for example, any metallic strip, flat bar, fiat band, plate, or flat sheet. As illustrated the skelp is conveyed from a clipping or skelp pointing shear as In, to a fixed or non-traveling charging device of any suitable character designated by the numeral II, by chain conveyors i2, the latter being driven by some suitable means, as a sprocket drive, Fig. 2. The skelp charger H is located directly in line with the small charging opening 8 and operates to charge the skelp one piece at a time, into the heating chamber of the furnace onto a conveyor means extending through and operable in the furnace in planes at right angles with the charging machine and the charging opening 8. Any suitable type of charger may be used, the charger shown includes rolls 1'. adapted to be driven by a motor m and an intermediate chain and sprocket drive.

As shown, the conveyor means l3 operable within the heating chamber include a plurality of metallic chains l3, adapted to be driven by a motor It, with the upper and lower runs thereof extending through openings l8 and H in the side walls l8 and IQ of the furnace. 20 designates a drive shaft supported by bearing brackets 2| on furnace side wall 18, said shaft being driven by a chain or belt 22 extending from the motor M, and provided with sprocket wheels 23 for chains I3. Located on similar brackets 24 on side wall I9 is a shaft 25 having sprockets 26 for engagement with the conveyor chains. It is evident that other well known types of conveyor means may be employed for those illustrated without departing from 'my invention.

It may be desirable in ome instances to employ a fluid cooled track or rail for the conveyor chains. Such a construction is shown and includes a tubular member 2! formed with a channel 28 adapted to receive a portion of the chain therein during the travel of the chain through the heating chamber of the furnace. Cooling fluid is fed to and from member 21 from a suitable source through pipes 29.

Located adjacent the front or skelp withdrawal end of the furnace and directly in line with the opening 9, is a non-traveling draw-bench 30. This draw-bench includes the usual instrumentalities for drawing the pieces of skelp one at a time from off the conveyor l3 and forming the skelp into welded pipe or tubing. This drawbench includes a bell or die 3|, tongs 32, a chain 33 driven by a motor 34; the tongs are connected with and disconnected from the chain by means of a hook.

The welder operating at the front end of the furnace which, in the present case is closed by a solid wall, except the relatively small opening 8, may without being affected by the heat of the furnace and working close to the front wall clamp the point or sheared end of the skelp with the tongs, slipping the tongs through the bell or die, then drops the hook of the tongs on the drawbench chain, after which the skelp is drawn into the bell and the pipe formed.

In practice, the speed of travel of the skelp conveyor through the practically closed heating chamber to impart the desired temperature to the individual pieces of skelp at the time the respective pieces are passed into alinement with the draw-opening, may be predetermined. The speed of the motor H is controlled and regulated to produce the desired speed of travel of the said conveyor whereby the skelp, approximately throughout its entire length, is heated to a uniform and desired temperature for the pipe forming and welding operations.

I claim:

1. In the art of manufacturing pipe or tubing embodying the draw-bench bell-weld method, a process which consists in subjecting individual spaced apart pieces of flat skelp all on a common horizontal plane, to the temperature of an approximately closed heating chamber of a furnace while moving the skelp edgewise on such horizontal plane with continuous motion therethrough at a predetermined speed to produce bell-welding temperature especially as to oppo-.

site edges of the skelp whereby to ensure welding connection thereof, and drawing the heated skelp through a die of a draw-bench on said plane for final tube forming operation therein.

2. Inthe art of manufacturing pipe or tubing embodying the draw-bench bell-weld method, a continuous process which consists in mechanically conveying individual spaced apart pieces of flat skelp edgewise to a heating furnace, mechanically introducing the pieces lengthwise to the heating chamber of the furnace on a common plane, subjecting the skelp and its edges to the temperature of the heating chamber while moving the spaced apart skelp edgewise with continuous travel therethrough at a predetermined speed of travel to produce bell-welding temperature, and drawing the heated skelp through a die of a draw-bench for final edge welding and tube forming operation therein.

3. The herein described method of manufacturing pipe or tubing consisting in introducing fiat skelp units individually through an endmost receiving opening to the interior of a heating furnace on a common plane, moving the skelp edgewise in successively accumulating spaced apart series through a closed air-protected main portion of the furnace to subject the flat skelp and their edges to ample heat exposure to gradually bring the advancing skelp to suitable welding temperature and into register with a diagonally opposite delivery opening, and then succesively withdrawing the heated skelp through such delivery opening and through a forming and welding die.

4. The herein described method of manufacturing pipe or tubing consisting in introducing flat skelp units individually through an endmost receiving opening to the interior of a heating furnace, moving the skelp edgewise on a common plane at a predetermined speed in succes sively accumulating spaced apart series through a closed air-protected main portion of the furnace to gradually bring the advancing skelp and edges thereof to suitable welding temperature and into register with a diagonally opposite delivery opening, and then sucessively withdrawing the heated skelp through such delivery opening and through a forming and welding die.

5. In apparatus for the continuous making of pipe or tubing from fiat skelp under the drawbench bell-weld method, the combination with an approximately closed furnace heating chamber having a relatively small charging opening in a wall thereof and a relatively small skelp exit opening in an opposite wall diagonally opposite the charging openings, a skelp charging device, means for moving skelp edgewise to the charger, a speedcontrolled skelp conveyor operable within the chamber for moving spaced apart flat skelp edgewise with continuous motion and at a predetermined speed of travel between said openings, said charger and conveyor operating on a common plane, and a draw-bench adjacent the exit opening. I

6. In apparatus for the manufacture of tubing or pipe, the combination with a skelp heating chamber of a furnace having only a relatively small skelp charging opening in a wall thereof and only a relatively small exit opening for the skelp out of line with the said first opening in an opposite furnace wall, a conveyor operable in the heating chamber for moving flat spaced apart skelp edgewise from the charging opening to the exit opening on a continuous common level plane, a skelp charger positioned adjacent the charging opening for charging individual pieces lengthwise through 'said opening and onto the conveyor within the heating chamber, and a pipe draw-bench and die arranged adjacent the exit opening for moving the heated skelp from the conveyor lengthwise and subjecting the flat skelp to final tube-forming and welding operation therein.

7. In apparatus for the manufacture of tubing or pipe, the combination with a skelp heating chamber of a furnace having a skelp charging opening in a wall thereof and an exit opening for the skelp in an opposite wall, a horizontal speed controlled conveyor operable in the heating chamber for moving fiat spaced apart skelp edgewise from the charging opening to the exit opening with continuous mot on at a predetermined speed and on a common plane, a skelp charger positioned adjacent the charging opening for charging individual pieces lengthwise through said opening and onto the conveyor within the heating chamber, and a pipe drawbench and die arranged adjacent the exit opening for moving the heated skelp lengthwise from the conveyor and subjecting the fiat skelp to final tube-forming and welding operation therein.

8. In combination, a temperature conserving skelp heating furnace having rear, front and side walls, the rear and front walls having individual diagonally opposite small receiving and delivery openings of just suflicient size to permit passage therethrough of fiat cold and hot skelp respectively, means for movingseries of spaced apart flat skelp through the furnace edgewise between the rear and front walls on a common level plane, means for charging individual skelp through the opening in the rear wall onto the moving means on said plane, and a draw-bench and welding die located in register with the discharge opening for individual withdrawal therethrough of heated skelp and tubular formation and edge welding thereof.

9. In combination, a temperature conserving skelp heating furnace having rear, front and side walls, the rear and front walls having individual diagonally opposite small receiving an delivery openings of just sufficient size to permit passage therethrough of cold and hot skelp respectively, supporting and conveying chains for moving spaced apart skelp through the furnace edgewise between the rear and front walls, fluid circulating cooling supports for said chains, means for charging individual skelp through the opening in the rear wall onto the moving means, and a draw-bench and welding die located in register with the discharge opening for indiv dual withdrawal therethrough of heated skelp and formation and welding thereof.

JOHN E. SHOCK. 

